1. Field of the Invention
The present invention relates to a terminal crimping apparatus for caulking, inside of the connector housing a crimp terminal loaded in the connector housing to crimp an end of an electric wire on the crimp terminal onto an end of an electric wire.
2. Description of the Related Art
Crimping connectors using terminal fittings of an electric wire crimping type have been used as wiring harnesses for appliances, automobiles and the like.
In manufacturing wiring harnesses for appliances,
i) Electric wires having a single thickness are used.
ii) In many cases, wiring harnesses are wired by so-called parallel wiring (corresponding ones of a plurality of terminals in a pair of connector housings are wired to have a one-to-one correspondence with each other).
iii) Moreover, wiring harnesses conforming to the same specification are manufactured in large quantities.
With respect to such wiring harnesses for appliances which use electric wires having a single thickness, are wired by parallel wiring and are mass-produced (for example, flat cables), there has been provided a terminal crimping apparatus of a simultaneous crimping type using comb-shaped crimpers and anvils and simultaneously caulking electric wires to respective crimp terminals loaded into connector housings (see Japanese Patent Laid-Open Gazette No. 98278/1991). The manufacture of the wiring harnesses for appliances can be automated relatively easily using the above described terminal crimping apparatus of a simultaneous crimping type.
On the other hand, in wiring harnesses for automobiles and the like,
i) Electric wires having a plurality of different thicknesses are used.
ii) Furthermore, wiring harnesses are not wired by so-called parallel wiring. Specifically, ends of two electric wires are crimped on some crimp terminals. Alternatively, terminals in a plurality of connector housings are connected to one terminal in one connector housing. The assembled state of wiring harnesses wired by nonparallel wiring is illustrated in a simplified manner in FIG. 8. In FIG. 8, reference numeral 100 denotes a connector housing, reference numeral 101 denotes a thin electric wire, and reference numeral 102 denotes a thick electric wire. In addition, reference numeral 103 indicates a portion where two electric wires are crimped on the same crimp terminal.
iii) Additionally, in recent automobiles, a great deal of options are set for electronic components in addition to the fact that a great deal of grades are set in one type of automobile. Therefore, as wiring harnesses which are adapted to the automobiles, wiring harnesses conforming to a great deal of specifications must be manufactured. Moreover, the number of wiring harnesses conforming to each of the specifications to be manufactured is not too large. That is, few-of-a-kind wiring harnesses are forced to be produced.
With respect to such wiring harnesses for automobiles and the like which use electric wires having a plurality of thicknesses, which are wired by nonparallel wiring and which are the produced on a few-of-a-kind basis, there are following problems, so that a terminal crimping apparatus of a simultaneous crimping type cannot be applied to the manufacture thereof. Specifically,
i) When one connector housing has n terminals, there are 3.sup.n combinations as combinations in crimping respective ends of three types of electric wires, that is, one thin electric wire, two thin electric wires and a thick electric wire on the respective terminals. Three types of crimp terminals are used to correspond to the three types of electric wires. When the crimping is completed, the heights of the three types of crimp terminals differ from each other. When the three types of electric wires are crimped using a crimping apparatus, a stroke for pressing a crimper serving as a pressing member against the crimp terminal received by an anvil serving as a pressure receiving member differs depending on the type of crimp terminal.
In the above described type of simultaneously crimping a plurality of terminals in one connector housing, therefore, a lot of, that is, the above described 3.sup.n (81 n=4) comb-shaped crimpers and anvils which are adapted thereto must be produced to stand by as required. Work (rearrangement) selecting required crimpers and anvils conforming to the specification of the connector housing out of the above described crimpers and anvils to replace them is required. Therefore, it has been difficult to apply the simultaneous crimping type to the automation of the manufacture of wiring harnesses because it is too complicated. Moreover, few-of-a-kind wiring harnesses are produced, so that the rearrangement must be frequently made. Consequently, the simultaneous crimping type which requires complicated rearrangement is more unsuitable for the automation.
ii) Furthermore, in the simultaneous crimping type, the order of crimping is specified for each connector housing, so that the following situations arise. Specifically, when a crimp terminal in one connector housing is crimped, a plurality of electric wires which should be crimped on the above described crimp terminal in the one connector housing may, in some cases, include an electric wire having its end already crimped on a crimp terminal in another connector housing. In this case, the other end of the electric wire whose one end is crimped on the crimp terminal in the above described one connector housing cannot be crimped until the crimping process of the one connector housing. As a result, a lot of electric wires must wait in a state where one end of each of the electric wires is hung on the crimp terminal in the above descried other connector housing until the crimping process of the other connector housing. Moreover, the destinations of the other ends of the electric wires must be respectively judged. Consequently, it is extremely difficult to apply the simultaneous crimping type to the automation of the manufacture of wiring harnesses because the crimping process becomes enormously complicated.